Illumination is very critical in photography and when a flashlamp is used, difficulties are encountered because of transmission of the light from only one direction. Professional photographers use a plurality of light sources to avoid such problems, sometimes using "bounce" lighting in which the light is directed toward a ceiling, wall or other object to be diffusely reflected toward the region to be photographed and to obtain a more uniform lighting with minimal shadows. Amateur photographers are not usually in a position to use plural light sources and have generally been limited to the use of a single source with consequent difficulties.
Automatic flash units are well-known in which the amount of light used to illuminate a region may be controlled automatically using a photometric device responsive to light reflected back from the region. It has been proposed to construct a flash unit with two flash sections which are turned on simultaneously with at least one of such sections being rotatable in a manner such that bounce lighting may be used. However, there are problems which are not fully recognized and dealt with with a device of this type as proposed. In particular, a fixed ratio between the bounce light and the direct light has been proposed such as a ratio of approximately four to one. It has been found, however, that with such a ratio, the effective value of the direct light may be much greater than that of the bounce light and the relative effect may also be changed with different conditions. In addition, it is not possible to reliably obtain the proper total amount of light with arrangements as heretofore proposed.